/* ==========================================================================
   Light Neat Theme 1 — markdown-it-customize
   Google Fonts: Figtree (headings) · Source Sans 3 / Cardo / Caveat / Fira Code (body options)

   Optional modifiers on <body> or .markdown-body:
   - .font-serif
   - .font-sans
   - .font-handwritten
   - .font-typewrite
   - .size-xs | .size-sm | .size-lg | .size-xl
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Figtree:wght@500;600;700;800&family=Source+Sans+3:wght@400;500;600;700&family=Cardo:ital,wght@0,400;0,700;1,400&family=Caveat:wght@500;600;700&family=Fira+Code:wght@400;500;600&display=swap');
@import './common.css';

:root {
  color-scheme: light;

  --bg: #f7f9fb;
  --bg-soft: #ffffff;
  --surface: #ffffff;
  --surface-2: #f5f9fd;
  --surface-3: #eef4fa;
  --border: #d7e3ef;
  --border-strong: #bdd1e3;
  --border-soft: #e6eef5;

  --text: #22313f;
  --text-soft: #587085;
  --text-muted: #7c92a4;
  --heading: #142230;

  --accent: #2e8bcf;
  --accent-2: #62b0e8;
  --accent-strong: #255d9d;
  --accent-warm: #48b7a8;
  --accent-grid: rgba(46, 139, 207, 0.08);

  --link: #1768b5;
  --link-hover: #0f4d86;
  --link-visited: #5b6fc8;

  --code-bg: #f4f9fd;
  --code-bg-2: #eef6fb;
  --code-border: #d4e3f0;
  --code-text: #23405f;
  --inline-code: #0f6894;

  --success-bg: rgba(72, 184, 143, 0.11);
  --success-border: #8fd9bc;
  --success-text: #167857;

  --note-bg: rgba(108, 126, 227, 0.1);
  --note-border: #bcc7fb;
  --note-text: #4550a8;

  --info-bg: rgba(70, 154, 230, 0.1);
  --info-border: #abd4f4;
  --info-text: #1266a7;

  --warning-bg: rgba(232, 181, 63, 0.12);
  --warning-border: #efd28a;
  --warning-text: #8e6413;

  --danger-bg: rgba(223, 108, 119, 0.11);
  --danger-border: #efb0b8;
  --danger-text: #a14153;

  /* coloured spans: OKLCH chroma >= 0.13, >= 5:1 on the page */
  --span-red: #bf3940;
  --span-yellow: #5c4300;
  --span-yellow-bg: rgba(255, 210, 48, 0.42);
  --span-green: #0d7a3e;
  --span-blue: #006cba;

  /* callout icon discs: vivid symbol ink per type */
  --success-mark: #138a5f;
  --note-mark: #4e5ccc;
  --info-mark: #1a74c4;
  --warning-mark: #a06b00;
  --danger-mark: #c23b4e;

  --font-heading: 'Figtree', system-ui, 'Noto Sans SC', 'Noto Sans TC', sans-serif;
  --font-body: 'Source Sans 3', system-ui, 'Noto Sans SC', 'Noto Sans TC', sans-serif;
  --font-code: 'Fira Code', 'JetBrains Mono', monospace;
  --base-size: 1.0625rem;
  --line-height: 1.7;
  --font-scale: 1;
  --lh-copy: var(--line-height);
  --lh-tight: 1.24;

  --fs-50: calc(0.78 * var(--base-size) * var(--font-scale));
  --fs-75: calc(0.9 * var(--base-size) * var(--font-scale));
  --fs-100: calc(var(--base-size) * var(--font-scale));
  --fs-200: calc(1.14 * var(--base-size) * var(--font-scale));
  --fs-300: calc(1.28 * var(--base-size) * var(--font-scale));
  --fs-400: calc(1.55 * var(--base-size) * var(--font-scale));
  --fs-500: calc(1.95 * var(--base-size) * var(--font-scale));
  --fs-600: calc(2.5 * var(--base-size) * var(--font-scale));

  --space-1: 0.35rem;
  --space-2: 0.65rem;
  --space-3: 0.95rem;
  --space-4: 1.35rem;
  --space-5: 1.9rem;
  --space-6: 2.7rem;

  --radius-sm: 8px;
  --radius: 16px;
  --radius-lg: 28px;
  --shadow: 0 18px 42px rgba(86, 125, 155, 0.12);
  --shadow-soft: 0 8px 24px rgba(96, 129, 155, 0.08);
  --transition: 180ms ease;

  /* markdown body container toggles */
  /* ~70 characters of Source Sans 3 per line, plus the article's own padding */
  --markdown-body-max-width: calc(36rem + 2 * var(--markdown-body-padding));
  /* .measure-wide: ~90 characters per line */
  --orz-measure-wide: calc(45rem + 2 * var(--markdown-body-padding));
  --markdown-body-padding: clamp(1.25rem, 3.6vw, 3.2rem);
  --markdown-body-border: none;
  --markdown-body-radius: 0;
  --markdown-body-shadow: none;
  --markdown-body-decorations-display: none;
  /* charts and diagrams (2.4.0): Chart.js and Mermaid read these (references/themes.md) */
  --chart-text: #587085;
  --chart-grid: rgba(34, 49, 63, 0.12);
  --chart-1: #2e8bcf;
  --chart-2: #48b7a8;
  --chart-3: #f0a33b;
  --chart-4: #e0607e;
  --chart-5: #5b6fc8;
  --chart-6: #8fb33c;
  --mm-text: #22313f;
  --mm-line: #587085;
  --mm-node: #eef4fa;
  --mm-border: #2e8bcf;
  --mm-accent: #48b7a8;
  --mm-note: #fff4d6;
}

body.font-serif,
.markdown-body.font-serif {
  --font-body: 'Cardo', Georgia, 'Noto Serif SC', 'Noto Serif TC', serif;
  --lh-copy: 1.82;
}

body.font-sans,
.markdown-body.font-sans {
  --font-body: 'Source Sans 3', system-ui, 'Noto Sans SC', 'Noto Sans TC', sans-serif;
}

body.font-handwritten,
.markdown-body.font-handwritten {
  --font-body: 'Hanzi Pen TC', 'Hanzi Pen SC', 'Caveat', 'Segoe Print', cursive;
  --lh-copy: 1.88;
}

body.font-typewrite,
.markdown-body.font-typewrite {
  --font-body: 'Fira Code', monospace;
  --lh-copy: 1.78;
}

body.size-xs,
.markdown-body.size-xs {
  --font-scale: 0.9;
}

body.size-sm,
.markdown-body.size-sm {
  --font-scale: 0.96;
}

body.size-lg,
.markdown-body.size-lg {
  --font-scale: 1.08;
}

body.size-xl,
.markdown-body.size-xl {
  --font-scale: 1.16;
}

html, body, :where(.markdown-body), :where(.markdown-body) *, :where(.markdown-body) *::before, :where(.markdown-body) *::after {
  box-sizing: border-box;
}

html {
  font-size: 100%;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  padding: clamp(0.9rem, 2.5vw, 2rem);
  background:
    radial-gradient(circle at top left, rgba(98, 176, 232, 0.06), transparent 28%),
    radial-gradient(circle at top right, rgba(72, 183, 168, 0.05), transparent 22%),
    linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 100%);
}

:where(.markdown-body) {
  /* Typography lives on the article, not the page: a host page's own UI keeps its fonts and colours (M.14). */
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-100);
  line-height: var(--lh-copy);
}

::selection {
  background: rgba(98, 176, 232, 0.2);
  color: var(--heading);
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.4);
}

::-webkit-scrollbar-thumb {
  background: rgba(46, 139, 207, 0.24);
  border-radius: 999px;
  border: 2px solid rgba(255, 255, 255, 0.65);
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(46, 139, 207, 0.38);
}

.markdown-body {
  position: relative;
  margin: 0 auto;
  padding: var(--markdown-body-padding);
  background: transparent;
  border: var(--markdown-body-border);
  border-radius: var(--markdown-body-radius);
  box-shadow: var(--markdown-body-shadow);
  overflow: hidden;
  isolation: isolate;
}

.markdown-body::before {
  display: var(--markdown-body-decorations-display);
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, transparent 0, transparent 13px, var(--accent-grid) 13px, transparent 14px),
    linear-gradient(var(--accent-grid) 1px, transparent 1px);
  background-size: 14px 14px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.15), transparent 30%);
  opacity: 0.45;
  pointer-events: none;
  z-index: -1;
}

.markdown-body::after {
  display: var(--markdown-body-decorations-display);
  content: '';
  position: absolute;
  inset: 0 auto auto 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent-warm), transparent 88%);
  pointer-events: none;
}

.markdown-body > :first-child {
  margin-top: 0;
}

:where(.markdown-body) h1, :where(.markdown-body) h2, :where(.markdown-body) h3, :where(.markdown-body) h4, :where(.markdown-body) h5, :where(.markdown-body) h6 {
  clear: both;
  position: relative;
  margin: 2.15em 0 0.7em;
  color: var(--heading);
  font-family: var(--font-heading);
  line-height: var(--lh-tight);
  font-weight: 700;
  letter-spacing: -0.025em;
  text-wrap: balance;
  scroll-margin-top: 4rem;
}

:where(.markdown-body) h1:first-child,
:where(.markdown-body) h2:first-child,
:where(.markdown-body) h3:first-child {
  margin-top: 0;
}

:where(.markdown-body) h1 {
  margin-bottom: 0.9em;
  font-size: clamp(2rem, 4.4vw, 2.75rem);
  color: #173248;
  letter-spacing: -0.035em;
  text-align: center;
}

/* Neat 1's signature: a centred title closed by a small star between two sky-to-teal strokes */
:where(.markdown-body) h1::after {
  content: '\2726';
  display: block;
  width: 6rem;
  margin: 0.55rem auto 0;
  color: var(--accent-strong);
  font-size: 0.8rem;
  line-height: 1;
  letter-spacing: 0;
  text-align: center;
  background:
    linear-gradient(90deg, var(--accent-2), var(--accent-warm)) left center / 2rem 2px no-repeat,
    linear-gradient(90deg, var(--accent-warm), var(--accent-2)) right center / 2rem 2px no-repeat;
}

:where(.markdown-body) h2 {
  font-size: clamp(1.55rem, 3vw, 2.1rem);
  padding: 0 0 0.32em;
  color: var(--accent-strong);
  border-bottom: 1px solid var(--border-strong);
}

:where(.markdown-body) h2::after {
  display: none;
}

:where(.markdown-body) h3 {
  font-size: var(--fs-400);
  color: #1f536d;
}

/* a sky dot with a halo, hung in the gutter on the bullets' axis */
:where(.markdown-body) h3::before {
  content: '';
  position: absolute;
  left: -1.05rem;
  top: calc(var(--lh-tight) * 0.5em - 0.25rem);
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 0 4px rgba(98, 176, 232, 0.2);
  transition: opacity var(--transition);
}

:where(.markdown-body) h3:hover::before {
  opacity: 0;
}

:where(.markdown-body) h4 {
  font-size: var(--fs-300);
  color: #21485d;
  letter-spacing: -0.015em;
}

:where(.markdown-body) h5 {
  font-size: var(--fs-200);
  color: #365d78;
  letter-spacing: -0.01em;
}

:where(.markdown-body) h6 {
  font-size: var(--fs-75);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-soft);
}

:where(.markdown-body) .header-anchor {
  float: left;
  margin-left: -1.25em;
  padding-right: 0.3em;
  color: var(--accent);
  text-decoration: none;
  opacity: 0;
  transform: translateX(0.15em);
  transition: opacity var(--transition), transform var(--transition), color var(--transition);
}

:where(.markdown-body) h1:hover .header-anchor,
:where(.markdown-body) h2:hover .header-anchor,
:where(.markdown-body) h3:hover .header-anchor,
:where(.markdown-body) h4:hover .header-anchor,
:where(.markdown-body) h5:hover .header-anchor,
:where(.markdown-body) h6:hover .header-anchor {
  opacity: 0.75;
  transform: translateX(0);
}

:where(.markdown-body) .header-anchor:hover {
  color: var(--accent-strong);
}

:where(.markdown-body) p,
:where(.markdown-body) ul,
:where(.markdown-body) ol,
:where(.markdown-body) blockquote,
:where(.markdown-body) pre,
:where(.markdown-body) table,
:where(.markdown-body) .toc-wrapper,
:where(.markdown-body) details.spoil,
:where(.markdown-body) .tabs,
:where(.markdown-body) .cols,
:where(.markdown-body) .youtube-embed,
:where(.markdown-body) .mermaid,
:where(.markdown-body) .smiles-render {
  margin: 0 0 var(--space-5);
}

:where(.markdown-body) p {
  text-wrap: pretty;
}

:where(.markdown-body) p:last-child,
:where(.markdown-body) ul:last-child,
:where(.markdown-body) ol:last-child,
:where(.markdown-body) blockquote:last-child,
:where(.markdown-body) pre:last-child,
:where(.markdown-body) table:last-child {
  margin-bottom: 0;
}

:where(.markdown-body) a {
  color: var(--link);
  text-decoration-thickness: 1.4px;
  text-decoration-color: rgba(23, 104, 181, 0.28);
  text-underline-offset: 0.18em;
  transition: color var(--transition), text-decoration-color var(--transition);
}

:where(.markdown-body) a:hover {
  color: var(--link-hover);
  text-decoration-color: rgba(15, 77, 134, 0.56);
}

:where(.markdown-body) a:visited {
  color: var(--link-visited);
}

:where(.markdown-body) strong {
  color: var(--heading);
  font-weight: 700;
}

:where(.markdown-body) em {
  color: #355772;
}

:where(.markdown-body) s,
:where(.markdown-body) del {
  color: var(--text-muted);
  text-decoration-color: rgba(155, 99, 111, 0.35);
}

:where(.markdown-body) mark {
  padding: 0.08em 0.28em;
  color: #0f3552;
  background: rgba(98, 176, 232, 0.24);
  border-radius: 4px;
}

:where(.markdown-body) ins {
  color: #177d69;
  text-decoration: underline wavy rgba(72, 183, 168, 0.75) 1.5px;
  text-underline-offset: 0.18em;
}

:where(.markdown-body) sub,
:where(.markdown-body) sup {
  font-size: 0.72em;
  color: var(--text-soft);
}

:where(.markdown-body) code {
  font-family: var(--font-code);
  font-size: 0.9em;
  color: var(--inline-code);
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 6px;
  padding: 0.12em 0.38em;
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
}

:where(.markdown-body) pre {
  position: relative;
  padding: 1.05rem 1.25rem;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 12px;
}

:where(.markdown-body) pre,
:where(.markdown-body) kbd,
:where(.markdown-body) samp {
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
}

:where(.markdown-body) pre code {
  display: block;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--code-text);
  font-size: 0.875em;
  line-height: 1.7;
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
}

:where(.markdown-body) blockquote {
  padding: 0.95rem 1.25rem;
  color: #3b5a70;
  background: rgba(98, 176, 232, 0.07);
  border: 1px solid #dbeaf6;
  border-radius: 12px;
}

:where(.markdown-body) blockquote blockquote {
  margin-top: var(--space-4);
  background: rgba(255, 255, 255, 0.7);
}

:where(.markdown-body) blockquote > *:last-child {
  margin-bottom: 0;
}

:where(.markdown-body) ul,
:where(.markdown-body) ol {
  padding-left: 1.4rem;
}

:where(.markdown-body) li {
  margin-bottom: 0.42rem;
}

:where(.markdown-body) li > ul,
:where(.markdown-body) li > ol {
  margin-top: 0.42rem;
  margin-bottom: 0;
}

:where(.markdown-body) ul {
  list-style: none;
}

:where(.markdown-body) ul > li {
  position: relative;
}

:where(.markdown-body) ul > li::before {
  content: '';
  position: absolute;
  left: -1rem;
  top: 0.72em;
  width: 0.44rem;
  height: 0.44rem;
  border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 0 3px rgba(98, 176, 232, 0.15);
}

:where(.markdown-body) ol {
  list-style: decimal;
}

:where(.markdown-body) .task-list-item {
  padding-left: 0;
}

:where(.markdown-body) .task-list-item::before {
  display: none;
}

:where(.markdown-body) .task-list-item-checkbox,
:where(.markdown-body) .task-list-item input[type='checkbox'] {
  appearance: none;
  -webkit-appearance: none;
  position: relative;
  width: 1.05rem;
  height: 1.05rem;
  margin: 0 0.55rem 0 0;
  vertical-align: -0.12em;
  border: 1px solid #b8d0e4;
  border-radius: 6px;
  background: #fff;
}

:where(.markdown-body) .task-list-item-checkbox:checked,
:where(.markdown-body) .task-list-item input[type='checkbox']:checked {
  background: var(--accent);
  border-color: var(--accent);
}

:where(.markdown-body) .task-list-item-checkbox:checked::after,
:where(.markdown-body) .task-list-item input[type='checkbox']:checked::after {
  content: '';
  position: absolute;
  left: 0.29rem;
  top: 0.08rem;
  width: 0.24rem;
  height: 0.48rem;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

:where(.markdown-body) table {
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
}

:where(.markdown-body) thead th {
  padding: 0.82rem 1rem;
  background: #f1f7fc;
  border-bottom: 1px solid var(--border-strong);
  color: var(--heading);
  font-size: var(--fs-75);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

:where(.markdown-body) tbody td {
  padding: 0.86rem 1rem;
  border-bottom: 1px solid var(--border-soft);
  vertical-align: top;
}

:where(.markdown-body) tbody tr:nth-child(even) td {
  background: rgba(98, 176, 232, 0.035);
}

:where(.markdown-body) tbody tr:hover td {
  background: rgba(72, 183, 168, 0.06);
}

:where(.markdown-body) tbody tr:last-child td {
  border-bottom: 0;
}

:where(.markdown-body) hr {
  height: 1px;
  margin: var(--space-6) 0;
  border: 0;
  background: linear-gradient(90deg, transparent, rgba(46, 139, 207, 0.45), rgba(72, 183, 168, 0.4), transparent);
}

:where(.markdown-body) img {
  margin: 0 auto;
  border: 1px solid #dde8f3;
  border-radius: 12px;
}

:where(.markdown-body) p > img {
  margin: 0;
  border-radius: 10px;
}

:where(.markdown-body) .footnote-ref {
  font-size: 0.85em;
}

:where(.markdown-body) .footnote-ref a,
:where(.markdown-body) .footnote-backref {
  color: var(--accent-strong);
  text-decoration: none;
}

:where(.markdown-body) .footnotes-sep {
  margin: var(--space-6) 0 var(--space-4);
}

:where(.markdown-body) .footnotes {
  padding-top: var(--space-2);
  color: var(--text-soft);
  font-size: var(--fs-75);
}

:where(.markdown-body) .footnotes ol {
  margin-bottom: 0;
}

:where(.markdown-body) .footnotes li {
  margin-bottom: 0.65rem;
}

:where(.markdown-body) .katex {
  color: #18314c;
  font-size: 1.06em;
}

:where(.markdown-body) .katex-display {
  padding: 0.9rem 1rem;
  background: #f7fbfe;
  border: 1px solid #e0ebf4;
  border-radius: 18px;
}

:where(.markdown-body) .katex-error {
  display: inline-block;
  padding: 0.2em 0.48em;
  color: var(--danger-text);
  background: rgba(223, 108, 119, 0.12);
  border: 1px solid var(--danger-border);
  border-radius: 10px;
  font-family: var(--font-code);
  font-size: var(--fs-75);
}

/* Callouts: icon-led cards. A round tinted disc at the start of the first line
   carries a CSS-drawn symbol (info i, note lines, success tick, warning !,
   danger x), so the type reads by shape as well as by colour. Text stays ink. */
:where(.markdown-body) div.success,
:where(.markdown-body) div.note,
:where(.markdown-body) div.info,
:where(.markdown-body) div.warning,
:where(.markdown-body) div.danger {
  --icon: var(--info-mark);
  --icon-size: 1.5rem;
  --icon-top: calc(1rem + (var(--lh-copy) * 1em - var(--icon-size)) / 2);
  position: relative;
  margin-bottom: var(--space-5);
  padding: 1rem 1.2rem 1rem 3.2rem;
  color: var(--text);
  border: 1px solid;
  border-radius: 14px;
}

/* the disc */
:where(.markdown-body) div.success::before,
:where(.markdown-body) div.note::before,
:where(.markdown-body) div.info::before,
:where(.markdown-body) div.warning::before,
:where(.markdown-body) div.danger::before {
  content: '';
  position: absolute;
  left: 1.05rem;
  top: var(--icon-top);
  width: var(--icon-size);
  height: var(--icon-size);
  border-radius: 999px;
  background: color-mix(in srgb, var(--icon) 16%, #fff);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--icon) 30%, transparent);
  pointer-events: none;
}

/* the symbol, drawn on a box centred over the disc */
:where(.markdown-body) div.success::after,
:where(.markdown-body) div.note::after,
:where(.markdown-body) div.info::after,
:where(.markdown-body) div.warning::after,
:where(.markdown-body) div.danger::after {
  content: '';
  position: absolute;
  left: 1.05rem;
  top: var(--icon-top);
  width: var(--icon-size);
  height: var(--icon-size);
  background-repeat: no-repeat;
  pointer-events: none;
}

:where(.markdown-body) div.info::after {
  background-image:
    radial-gradient(circle, var(--icon) 0 0.1rem, transparent 0.11rem),
    linear-gradient(var(--icon), var(--icon));
  background-size: 0.3rem 0.3rem, 0.16rem 0.48rem;
  background-position: 50% 0.36rem, 50% 0.74rem;
}

:where(.markdown-body) div.warning::after {
  background-image:
    linear-gradient(var(--icon), var(--icon)),
    radial-gradient(circle, var(--icon) 0 0.1rem, transparent 0.11rem);
  background-size: 0.16rem 0.5rem, 0.3rem 0.3rem;
  background-position: 50% 0.36rem, 50% 0.93rem;
}

:where(.markdown-body) div.note::after {
  background-image: linear-gradient(var(--icon), var(--icon)), linear-gradient(var(--icon), var(--icon)), linear-gradient(var(--icon), var(--icon));
  background-size: 0.66rem 0.13rem, 0.66rem 0.13rem, 0.42rem 0.13rem;
  background-position: 0.42rem 0.5rem, 0.42rem 0.7rem, 0.42rem 0.9rem;
}

:where(.markdown-body) div.danger::after {
  background-image: linear-gradient(var(--icon), var(--icon)), linear-gradient(var(--icon), var(--icon));
  background-size: 0.16rem 0.7rem, 0.7rem 0.16rem;
  background-position: center, center;
  transform: rotate(45deg);
}

:where(.markdown-body) div.success::after {
  left: calc(1.05rem + var(--icon-size) / 2 - 0.15rem);
  top: calc(var(--icon-top) + 0.36rem);
  width: 0.32rem;
  height: 0.62rem;
  border: solid var(--icon);
  border-width: 0 0.16rem 0.16rem 0;
  transform: rotate(45deg);
}

:where(.markdown-body) div.success {
  --icon: var(--success-mark);
  background: rgba(72, 184, 143, 0.09);
  border-color: var(--success-border);
}

:where(.markdown-body) div.note {
  --icon: var(--note-mark);
  background: rgba(108, 126, 227, 0.09);
  border-color: var(--note-border);
}

:where(.markdown-body) div.info {
  background: rgba(70, 154, 230, 0.09);
  border-color: var(--info-border);
}

:where(.markdown-body) div.warning {
  --icon: var(--warning-mark);
  background: rgba(232, 181, 63, 0.12);
  border-color: var(--warning-border);
}

:where(.markdown-body) div.danger {
  --icon: var(--danger-mark);
  background: rgba(223, 108, 119, 0.1);
  border-color: var(--danger-border);
}

:where(.markdown-body) div.success > p:first-child > strong:first-child,
:where(.markdown-body) div.success > p:first-child > b:first-child {
  color: var(--success-text);
}

:where(.markdown-body) div.note > p:first-child > strong:first-child,
:where(.markdown-body) div.note > p:first-child > b:first-child {
  color: var(--note-text);
}

:where(.markdown-body) div.info > p:first-child > strong:first-child,
:where(.markdown-body) div.info > p:first-child > b:first-child {
  color: var(--info-text);
}

:where(.markdown-body) div.warning > p:first-child > strong:first-child,
:where(.markdown-body) div.warning > p:first-child > b:first-child {
  color: var(--warning-text);
}

:where(.markdown-body) div.danger > p:first-child > strong:first-child,
:where(.markdown-body) div.danger > p:first-child > b:first-child {
  color: var(--danger-text);
}

:where(.markdown-body) div.success > *:last-child,
:where(.markdown-body) div.note > *:last-child,
:where(.markdown-body) div.info > *:last-child,
:where(.markdown-body) div.warning > *:last-child,
:where(.markdown-body) div.danger > *:last-child {
  margin-bottom: 0;
}

:where(.markdown-body) .left {
  padding: 0.85rem 0.95rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 16px;
  margin: 0 var(--space-5) var(--space-4) 0;
}

:where(.markdown-body) .right {
  margin: 0 0 var(--space-4);
}

:where(.markdown-body) details.spoil {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--surface-2);
}

:where(.markdown-body) details.spoil > summary {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.95rem 1.1rem;
  list-style: none;
  user-select: none;
  color: var(--heading);
  font-weight: 600;
  background: rgba(98, 176, 232, 0.06);
}

:where(.markdown-body) details.spoil > summary::-webkit-details-marker {
  display: none;
}

:where(.markdown-body) details.spoil > summary::before {
  content: '+';
  display: inline-grid;
  place-items: center;
  width: 1.45rem;
  height: 1.45rem;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--border-strong);
  color: var(--accent-strong);
  font-weight: 700;
  line-height: 1;
}

:where(.markdown-body) details.spoil[open] > summary::before {
  content: '–';
}

:where(.markdown-body) details.spoil[open] > summary {
  border-bottom: 1px solid var(--border-soft);
}

:where(.markdown-body) details.spoil > :not(summary) {
  padding: 1rem 1.1rem 1.1rem;
}

:where(.markdown-body) .tabs {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface-2);
}

:where(.markdown-body) .tabs-bar {
  gap: 0.4rem;
  padding: 0.5rem;
  background: rgba(98, 176, 232, 0.05);
  border-bottom: 1px solid var(--border-soft);
}

:where(.markdown-body) .tabs-bar-btn {
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 0.56rem 0.92rem;
  background: transparent;
  color: var(--text-soft);
  font: 700 var(--fs-75)/1.2 var(--font-heading);
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

:where(.markdown-body) .tabs-bar-btn:hover {
  color: var(--heading);
  border-color: var(--border);
  background: rgba(255, 255, 255, 0.7);
}

:where(.markdown-body) .tabs-bar-btn.active {
  color: #fff;
  background: var(--accent-strong);
  border-color: transparent;
}

:where(.markdown-body) .tab {
  padding: 1.1rem 1.2rem 1.25rem;
}

:where(.markdown-body) .tabs:not([data-js]) .tab + .tab {
  border-top: 1px solid var(--border-soft);
}

:where(.markdown-body) .cols {
  gap: 1rem;
}

:where(.markdown-body) .col {
  padding: 1rem 1.05rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 18px;
}

:where(.markdown-body) .col > *:last-child {
  margin-bottom: 0;
}

:where(.markdown-body) .toc-wrapper {
  position: relative;
}

:where(.markdown-body) nav.toc,
:where(.markdown-body) .toc-list {
  padding: 1rem 1.15rem;
  background: linear-gradient(180deg, rgba(98, 176, 232, 0.08), rgba(255, 255, 255, 0.82));
  border: 1px solid var(--border);
  border-radius: 20px;
}

:where(.markdown-body) nav.toc ul,
:where(.markdown-body) .toc-list ul {
  margin: 0;
  padding-left: 1.1rem;
}

:where(.markdown-body) nav.toc li,
:where(.markdown-body) .toc-list li {
  margin-bottom: 0.26rem;
}

:where(.markdown-body) nav.toc li::before,
:where(.markdown-body) .toc-list li::before {
  display: none;
}

:where(.markdown-body) nav.toc a,
:where(.markdown-body) .toc-list a {
  color: var(--text-soft);
  text-decoration: none;
}

:where(.markdown-body) nav.toc a:hover,
:where(.markdown-body) .toc-list a:hover {
  color: var(--accent-strong);
}

:where(.markdown-body) span.red {
  color: var(--span-red);
}

:where(.markdown-body) span.yellow { color: #976d01; } /* text colour only, like the other spans: the most saturated gold at AA on this page */

:where(.markdown-body) span.green {
  color: var(--span-green);
}

:where(.markdown-body) span.blue {
  color: var(--span-blue);
}

:where(.markdown-body) span.success,
:where(.markdown-body) span.info,
:where(.markdown-body) span.warning,
:where(.markdown-body) span.danger {
  gap: 0;
  padding: 0.18em 0.62em;
  border-radius: 999px;
  border: 1px solid;
  font-size: 0.82em;
  font-weight: 700;
  vertical-align: middle;
}

:where(.markdown-body) span.success::before,
:where(.markdown-body) span.info::before,
:where(.markdown-body) span.warning::before,
:where(.markdown-body) span.danger::before {
  content: none;
}

:where(.markdown-body) span.success {
  background: rgba(72, 184, 143, 0.14);
  color: var(--success-text);
  border-color: var(--success-border);
}

:where(.markdown-body) span.info {
  background: rgba(70, 154, 230, 0.14);
  color: var(--info-text);
  border-color: var(--info-border);
}

:where(.markdown-body) span.warning {
  background: rgba(232, 181, 63, 0.16);
  color: var(--warning-text);
  border-color: var(--warning-border);
}

:where(.markdown-body) span.danger {
  background: rgba(223, 108, 119, 0.15);
  color: var(--danger-text);
  border-color: var(--danger-border);
}

:where(.markdown-body) div.test-block {
  padding: 0.85rem 1rem;
  margin-bottom: var(--space-5);
  background: rgba(98, 176, 232, 0.1);
  border: 1px dashed rgba(46, 139, 207, 0.35);
  border-radius: 16px;
  color: var(--accent-strong);
  font-family: var(--font-code);
  font-size: var(--fs-75);
}

:where(.markdown-body) span.test-inline {
  display: inline-block;
  padding: 0.12em 0.4em;
  border-radius: 8px;
  border: 1px dashed rgba(46, 139, 207, 0.35);
  color: var(--accent-strong);
  background: rgba(98, 176, 232, 0.12);
  font-family: var(--font-code);
  font-size: 0.88em;
}

:where(.markdown-body) div.youtube-embed {
  border: 1px solid var(--border);
  border-radius: 20px;
  background: #ddebf5;
  box-shadow: var(--shadow-soft);
}

:where(.markdown-body) div.mermaid {
  padding: 1.25rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface-2);
}

:where(.markdown-body) div.smiles-render canvas,
:where(.markdown-body) canvas[data-smiles] {
  border-radius: 0;
  box-shadow: none;
}

:where(.markdown-body) span.qrcode {
  padding: 6px;
  vertical-align: middle;
  background: #fff;
  border-radius: 12px;
  box-shadow: var(--shadow-soft);
}

/* --------------------------------------------------------------------------
   Focus indicators
   -------------------------------------------------------------------------- */
:where(.markdown-body) a:focus-visible,
:where(.markdown-body) .tabs-bar-btn:focus-visible,
:where(.markdown-body) details.spoil > summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
  text-decoration: none;
}
:where(.markdown-body) .task-list-item-checkbox:focus-visible,
:where(.markdown-body) .task-list-item input[type='checkbox']:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

@media (max-width: 720px) {
  body {
    padding: 0.7rem;
  }

  .markdown-body {
    padding: 1.05rem;
    border-radius: 22px;
  }

  :where(.markdown-body) .left {
    margin: 0 0 var(--space-4);
  }

  :where(.markdown-body) .header-anchor {
    margin-left: -1.05em;
  }
}

@media print {
  body {
    padding: 0;
    background: #fff;
    color: #111;
  }

  .markdown-body {
    padding: 0;
    border: 0;
    box-shadow: none;
  }

  .markdown-body::before,
  .markdown-body::after,
  :where(.markdown-body) .header-anchor {
    display: none !important;
  }

  :where(.markdown-body) a {
    color: #0b57d0;
    text-decoration-color: currentColor;
  }

  :where(.markdown-body) pre,
  :where(.markdown-body) code,
  :where(.markdown-body) blockquote,
  :where(.markdown-body) .success,
  :where(.markdown-body) .note,
  :where(.markdown-body) .info,
  :where(.markdown-body) .warning,
  :where(.markdown-body) .danger,
  :where(.markdown-body) nav.toc,
  :where(.markdown-body) .toc-list,
  :where(.markdown-body) .col,
  :where(.markdown-body) details.spoil,
  :where(.markdown-body) div.mermaid,
  :where(.markdown-body) div.smiles-render {
    background: #fff !important;
    color: #111 !important;
    border-color: #d0d0d0 !important;
    box-shadow: none !important;
  }

  :where(.markdown-body) span.success,
  :where(.markdown-body) span.info,
  :where(.markdown-body) span.warning,
  :where(.markdown-body) span.danger {
    border-color: #bdbdbd !important;
    color: #111 !important;
  }
}

/* code: panel tint shows through (no white highlight.js inner box) */
.markdown-body pre code, .markdown-body pre code.hljs { background: transparent; padding: 0; }